-Evidence of biologic activity of GMI-1359 observed in Phase 1b clinical trial interim analysis-Preclinical data highlight anti-tumor activity in pancreatic cancer model with GMI-1757, a novel galectin-3 antagonist

GlycoMimetics, Inc. (Nasdaq: GLYC) today announces that an abstract presenting the interim analysis of a Phase 1b proof-of-concept study of GMI-1359, the Company’s dual antagonist of E-selectin and CXCR4, has been accepted for presentation at the American Association of Cancer Research (AACR) 2021 Annual Meeting, to be held virtually on April 10-15 and May 17-21. Preclinical studies indicate that targeting both E-selectin and CXCR4, a chemokine receptor, with a single compound could improve efficacy in the treatment of cancers that affect the bone and bone marrow, such as breast and prostate cancer. A second abstract also accepted for presentation highlights, for the first time, preclinical data in pancreatic cancer for the Company’s novel dual antagonist of galectin-3 and E-selectin, GMI-1757. The latter is featured as a late-breaking abstract on the compound’s impact on fibrosis, mononuclear cell infiltration, and anti-PD-L1 therapeutic activity in a pancreatic adenocarcinoma model.

GlycoMimetics Chief Executive Officer Rachel King said, “We look forward to sharing results from two programs in our advancing portfolio at the upcoming AACR meeting, including the interim analysis of Phase 1b clinical data supporting further advancement of the GMI-1359 program. We are extremely proud to be collaborating with the Duke Cancer Institute on this important work, which we believe holds great promise in delivering a novel approach to treating cancers with bone involvement.”

Details on GlycoMimetics e-presentations at the AACR Meeting are as follows:

Title:“Development of GMI-1359, a Novel Agent Targeting Tumor-microenvironment Cross-talk in Bone Metastatic Breast Cancer”

Presenter:Dorothy Sipkins, M.D., Ph.D., Duke Cancer Institute

Session:e-Presentation

Date and Time:Saturday, April 10, 2021 (available online through Monday, June 21)

Title:A novel glycomimetic compound (GMI-1757) with dual functional antagonism to E-selectin and galectin-3 attenuates fibrosis, facilitates mononuclear cell infiltration and optimizes anti-PD-L1 therapeutic activity in a pancreatic adenocarcinoma model

Presenter:William E. Fogler, M.D., GlycoMimetics

Session:e-Presentation

Date and Time:Saturday, April 10, 2021 (available online through Monday, June 21)

About GMI-1757

An innovative dual antagonist of E-selectin and galectin-3, GMI-1757 was described in a poster presented at the 2018 annual meeting of the American Society of Hematology. The poster showcased the anti-thrombotic activity of the dual antagonist and suggested the compound may be able to play a role in the treatment of a variety of cancers and fibrotic conditions.

About GMI-1359

GMI-1359 is designed to simultaneously inhibit both E-selectin and CXCR4. E-selectin and CXCR4 are both adhesion molecules involved in tumor trafficking and metastatic spread. Preclinical studies indicate that targeting both E-selectin and CXCR4 with a single compound could improve efficacy in the treatment of cancers that involve the bone marrow, such as AML and multiple myeloma, or in solid tumors that metastasize to the bone, such as prostate cancer and breast cancer, as well as in osteosarcoma, a rare pediatric tumor affecting about 900 adolescents a year in the United States. GMI-1359 has completed a Phase 1 clinical trial in healthy volunteers. A Phase 1b clinical study is underway in breast cancer patients and is designed to enable investigators to identify an effective dose of the drug candidate and to generate initial biomarker data around the drug’s activity. GMI-1359 has received Orphan Drug designation and Rare Pediatric Disease designation from the FDA for the treatment of osteosarcoma.

About GlycoMimetics, Inc.

GlycoMimetics is a biotechnology company with a focus in hematology-oncology and a pipeline of novel glycomimetic drugs, all designed to address unmet medical needs resulting from diseases in which carbohydrate biology plays a key role. GlycoMimetics' drug candidate, uproleselan, an E-selectin antagonist, was evaluated in a Phase 1/2 clinical trial as a potential treatment for AML and is being evaluated across a range of patient populations including in a Company-sponsored Phase 3 trial in relapsed/refractory AML. GlycoMimetics has an ongoing Phase 1b clinical trial evaluating GMI-1359, a combined CXCR4 and E-selectin antagonist, also a wholly-owned drug candidate. GlycoMimetics is located in Rockville, MD in the BioHealth Capital Region. Learn more at www.glycomimetics.com .

Forward-Looking Statements

This press release contains forward-looking statements. These forward-looking statements include those relating to the planned or potential clinical development of the Company’s product candidates, as well as the presentation of data from preclinical studies and clinical trials and the potential benefits and impact of the Company’s drug candidates. Actual results may differ materially from those described in these forward-looking statements. For a further description of the risks associated with these statements, as well as other risks facing GlycoMimetics, please see the risk factors described in the Company’s annual report on Form 10-K filed with the U.S. Securities and Exchange Commission (SEC) on March 2, 2021, and other filings GlycoMimetics makes with the SEC from time to time. Forward-looking statements speak only as of the date of this release, and GlycoMimetics undertakes no obligation to update or revise these statements, except as may be required by law.